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Author:
Barry Pearce
Project No. MOZ2094A
2 June 2017
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Report on Initial Laboratory Visits and Protocol for the PTS (Final)
.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page i
The views in this document are those of the authors and they do not necessarily reflect
the views of the Research for Community Access Partnership (ReCAP), or Cardno Emerging
Markets (UK) Ltd for whom the document was prepared.
Cover Image: Scenes from the laboratory visits
Quality assurance and review table
Version Author(s) Reviewer(s) Date
Draft Barry Pearce
Robert Geddes (Internal) 15 May 2017
Nkululeko Leta (ReCAP) Les Sampson (ReCAP)
29 May 2017
Final Barry Pearce 2 June 2017
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page ii
ReCAP Project Management Unit
Cardno Emerging Market (UK) Ltd
Oxford House, Oxford Road
Thame
OX9 2AH
United Kingdom
ReCAP Completion Report Template
ReCAP Database Details: Economic Growth through Effective Road Asset Management
Reference No: MOZ2094A Location Mozambique
Source of Proposal Tender Procurement
Method
Open Competitive Tendering
Theme Sub-Theme
Lead
Implementation
Organisation
Civil Design Solutions Partner
Organisation
Learning Matters etc
Total Approved
Budget
Total Used
Budget
Start Date 13 December 2016 End Date 31 January 2018
Report Due Date 13 January 2017 Date Received
Key Words
Materials, Quality Control, Capacity Development, Proficiency Testing
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page iii
Acronyms, Units and Currencies
$ United States Dollars
AASHTO American Association of State Highway and Transport Officials
ACV Aggregate Crushing Value
AFCAP Africa Community Access Partnership
AIV Aggregate Impact Value
ALD Average Least Dimension
ANE Administração Nacional de Estradas; National Road Administration
ARMFA African Road Maintenance Fund Association
ASCAP Asia Community Access Partnership
BS British Standard
CBR California Bearing Ratio
CDS Civil Design Solutions
CSIR Council for Scientific and Industrial Research
DCP Dynamic Cone Penetrometer
DFID Department for Further International Development
DIMAN Directorate of Maintenance
DIPLAN Directorate of Planning
DIPRO Directorate of Projects
DN Number of mm penetration per blow of a DCP
EU European Union
FACT Fines Aggregate Crushing Test
FI Fineness Index
FM Fineness Modulus
FWD Falling Weight Deflectometer
GM Grading Modulus
GPS Global Positioning System
ISO International Standards Organisation’s
INNOQ Instituto Nacional de Normalização e Qualidade
LL Liquid Limit
LNEC Laboratório Nacional de Engenharia Civil (Portugal)
LS Linear Shrinkage
LVR Low Volume Road
MCA Millennium Challenge Account
MDD Maximum Dry Density
NLA National Laboratory Association
NP Non Plastic
OMC Optimal Moisture Content
PMU Project Management Unit
PI Plasticity Index
PL Plastic Limit
PT Proficiency Testing
PTS Proficiency Testing Scheme
ReCAP Research for Community Access Partnership
RL Reference Laboratory
RTFOT Rolling Thin Film Oven Test
SA South Africa
SADCAS Southern African Development Community Accreditation Service
SANAS South African Accreditation Service
SANS South African National Standards
SE Sand Equivalent
SC Steering Committee
TMH Technical Methods for Highways
UK United Kingdom (of Great Britain and Northern Ireland)
UKAid United Kingdom Aid (Department for International Development, UK)
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page iv
Contents
Acronyms, Units and Currencies ............................................................................ iii
Contents ............................................................................................................... iv
1 Introduction .................................................................................................... 1
1.1 Background to the Project 1
1.2 Objectives 1
1.3 Approach 2
1.4 Purpose of this Report 2
2 Visit Programme and Objectives ...................................................................... 3
3 ANE Maputo laboratory .................................................................................. 4
3.1 Overview 4
3.2 MDD/CBR 4
3.3 Atterberg Limits 4
4 LEM laboratory - Maputo ................................................................................ 5
4.1 Overview 5
4.2 MDD/CBR 5
4.3 Atterberg 5
5 Geoma Laboratory - Maputo ........................................................................... 7
5.1 Overview 7
5.2 MDD/CBR 7
5.3 Atterberg 7
5.4 General points 7
6 SoilLab laboratory - Maputo ............................................................................ 9
6.1 Overview 9
6.2 MDD/CBR 9
6.3 Atterberg 9
6.4 General points 9
7 JJR quarry ..................................................................................................... 10
7.1 Overview 10
7.2 Use of JJS Material in the PTS 10
8 JJR laboratory ............................................................................................... 11
8.1 Overview 11
8.2 General 11
8.3 Riffling 11
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page v
8.4 MDD/CBR 11
8.5 Atterberg 11
8.6 Aggregates 12
9 Inhambane - ANE .......................................................................................... 13
9.1 General 13
9.2 Riffling 13
9.3 MDD/CBR 13
9.4 Atterberg 13
10 Chimoio - ANE ............................................................................................... 15
10.1 General 15
10.2 MDD/CBR 15
10.3 Atterberg 15
11 Nampula - ANE .............................................................................................. 16
11.1 General 16
11.2 MDD/CBR 16
11.3 Atterberg 16
11.4 Second laboratory facility (approx. 20 km outside of Nampula) 17
12 Summary of main points observed ................................................................ 18
12.1 Mixing of methods between TMH1 and AASHTO 18
12.2 Methods not being followed correctly 18
12.3 Additional steps or apparatus added to methods 18
12.4 Equipment calibration and verification 18
12.5 Staff competency 18
12.6 Test Methods 19
13 The way forward ........................................................................................... 20
13.1 PTS Protocols 20
13.2 Follow-up PTS rounds 20
13.3 Participating Laboratories 20
Annex A: Draft Protocol for First Round of PTS .................................................... A1
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page 1
1 Introduction
1.1 Background to the Project
The Africa Community Access Partnership (AfCAP) is building on the programme of high
quality research established under AfCAP phase 1 and taking this forward to a sustainable
future. The aim is to ensure that the results of the research are adopted in practice and
influence future policy in the roads sector.
As part of this initiative AfCAP is providing a range of support to Mozambique, which is one
of 12 countries in Africa that are participating in AfCAP. This support includes the
development of design guidelines for low volume roads and the evaluation of existing road
experimental sections constructed previously in Mozambique.
The validity of research on roads in Mozambique and the region depends on the reliability of
laboratory test results. As a result, AfCAP is supporting the implementation of a pilot project
for Proficiency Testing in selected laboratories. The overall objective is to establish laboratory
testing in Mozambique that is “in line with international practices and standards and test
results that can be used with confidence”1.
The Proficiency Testing Scheme (PTS) will determine a baseline for the precision limits for
each specific test included in the project. The baseline will be used to assess laboratory
capacity and identify where the constraints lie and where specific training and other
interventions may be required. It is expected that participating laboratories will ultimately
become accredited to the International Standards Organisation’s standard ISO/IEC 17025.
The Mozambique PTS project is a pilot project for Mozambique and for a possible AfCAP
regional initiative to support capacity development in materials laboratory testing through a
PTS process.
1.2 Objectives
The objectives of the assignment are as follows:
• To identify the repeatability and reproducibility (precision limits) of the principal test
methods currently being carried out in Mozambican laboratories; evaluate the
existing testing competence of laboratories in Mozambique.
• Determine how the test results of the Mozambican laboratories compare with those
of internationally accredited (ISO/IEC 17025) laboratories and included these
laboratories as independent controls in the baseline survey and PTS pilot.
• Identify where interventions are needed for improving test results and the type of
intervention required.
1 Terms of Reference.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page 2
• Design and manage a pilot PTS and transfer knowledge and expertise to Mozambican
laboratory personnel on how to implement a PTS and to evaluate the test results
obtained.
• Keep ANE and sector stakeholders fully informed on project implementation and
outcomes in order for precision limits of tests to be included in relevant National
Standards for Roads in Mozambique.
1.3 Approach
The approach to the project implementation focuses on the following key objectives:
1. To ensure that ANE and LEM are the leaders of the research process.
2. To ensure effective linkages with parallel and associated project initiatives.
3. Establish linkages between the participating laboratories.
The purpose of establishing linkages between the participating laboratories is to promote the
concept of a self-supporting network of laboratories, with a joint commitment to quality and
reliability of results.
1.4 Purpose of this Report
This report covers the field visit of the CDS Materials Engineer to conduct an initial assessment
of laboratories that were shortlisted to participate in the project. The shortlisting was carried
out through a questionnaire sent by ANE to all known materials laboratories in the country.
The report includes the draft protocol for conducting the first round of the PTS pilot (see
Annex A).
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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2 Visit Programme and Objectives
The laboratory audits were conducted between the 20th and 31st March 2017. The team
included representatives of ANE, LEM as well as Mr Barry Pearce from the Consultant,
CDS/LMetc.
A briefing meeting was held on 20th March at ANE’s offices where feedback was provided on
the analysis of the questionnaire circulated to 27 laboratory facilities in Mozambique. The
approach to the laboratory assessments was outlined at the meeting including a discussion
on the preferred test methods likely to be used by ANE in future contract documentation.
The visit itinerary was as follows:
• Monday 20th March: Arrive Maputo. Briefing meeting at ANE.
• Tuesday 21st March: Visit laboratories in Maputo (ANE Maputo, LEM, Geoma)
• Wednesday 22nd March: Visit laboratories in Maputo (SoilLab, JJR)
• Thursday 23rd March: Travel to Inhambane
• Friday 24th March: Visit Inhambane laboratory and return to Maputo
• Tuesday 28th March: Travel to Chimoio, visit ANE Manica laboratory
• Wednesday 29th March: Travel from Chimoio to Nampula
• Thursday 30th March: Visit ANE Nampula laboratories and return to Maputo
• Friday 31st March: Debriefing at ANE and end of mission.
The findings from each laboratory visit are summarised in the following sections.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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3 ANE Maputo laboratory
3.1 Overview
There are limited testing facilities in the laboratory with the main emphasis being soils and
concrete.
The following points were noted during the assessment of this facility on 21st March.
3.2 MDD/CBR
1. Mould base plate not fixed to the floor during compaction resulting in a loss of compaction
effort.
2. CBR mould surcharge covered with water resulting in variable loading to the specimens.
3. Soaking base plate drainage holes blocked and need to be cleaned after each use to
ensure moisture flow into the samples can occur during soaking period.
3.3 Atterberg Limits
1. No bowl used for mixing. The material is mixed on a glass plate resulting in possible
moisture loss over the duration of the test method.
2. Liquid Limit (LL) grooving done towards back of bowl. This is a good process as it affects
the material in the bowl less than cutting forwards.
3. Tapping of LL device too slow.
4. No timing devices in the facility to check for soaking periods and other timing issues.
5. 10 mm drop checked off the back of the grooving tool which is not a calibrated device.
6. The depression in the base plate of the LL device needs to be checked so as not to affect
the distance the bowls falls through with each tap. The depression looks already to be
too large to conform to the tolerance allowed.
7. No records of measurement for calibration or verifications. This is a traceability issue
which would ensure better correlation in measurements between different facilities.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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4 LEM laboratory - Maputo
4.1 Overview
This is an extensive laboratory facility with diverse testing ability. All the equipment looks new
and in a good condition.
The following points where noted during the assessment of this facility on 21st March
4.2 MDD/CBR
1. TMH1 Methods A7 used. Sample is a sandy red/brown local material.
2. Sample once mixed not covered so moisture loss possible during compaction of the 5
layers.
3. Each layer not measured to check height and then next layer’s mass not weighed off to
ensure correct height increase for each layer.
4. Hammer bouncing too high between each blow resulting in more compaction if the
hammer kept closer to the surface being compacted. Hand compaction used.
5. Moisture tins possibly too deep resulting in more time required to dry the samples. If
not fully dried when removed from the oven it can lead to lower moisture contents
being recorded. Larger flatter open pans could be more effective for the moisture
content determinations. The samples will also tend to dry quicker if in a flatter pan.
6. Base of hammer not cleaned of material build-up between layers resulting on a curved
compaction surface as against a flat face.
7. Base plate fixed to a concrete plinth on the ground.
8. No conditioning period of 30 minutes as per TMH1 once moisture mixed into each
sample.
9. Mould used conforms to AASHTO dimensions and not TMH1 dimensions. Surcharge lies
below the mould lip and therefore can’t conform to the correct water height in the
soaking bath. Water level covers both mould lip and surcharge.
4.3 Atterberg
1. The National Portuguese standards & AASHTO methods tend to have the sample dished
in the LL bowl as against parallel with the base plate which is difficult to keep constant
between laboratories building in more variability.
2. Taps for the LL methods within acceptable tolerance.
3. No block to check height drop for LL device. Back of grooving tool used to check height.
4. Starts LL on the wet side and dries material to a dryer state. Additional dry material is
added to reduce moisture which can build in variability. It was stated that this was
checked during an Inter-Laboratory Comparison (ILC) and found not to affect the results.
5. LL determined off 4 points.
6. Plastic Limit (PL) was rolled out on dry material to assist in the drying process. Again, this
can affect the result as the outer dryer material could be in a different moisture state than
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page 6
the existing material that has be moistened for a longer period of time. The material is
worked by hand and rolled out well.
7. Gauging the 3mm thread thickness is done by eye.
8. Linear Shrinkage (LS) is done using the square TMH1 trough & not the AASHTO method.
9. All results recorded in a bound book.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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5 Geoma Laboratory - Maputo
5.1 Overview
This is a very compact laboratory setup in a residential area of Maputo.
The following points where noted during the assessment of this facility on 21st March
5.2 MDD/CBR
1. MDD sample exposed to heat and not covered after mixing therefore moisture loss
occurring during the 5 layers being compacted.
2. Moisture taken at the start and not after the 2nd layer as per test method.
3. No 30-minute conditioning period for soaking after water mixed in for each sample.
4. No control over the height of each layer and the material mass added per layer. The
standard approach using a fixed mass per layer is used. The material is scooped out of the
basin and added to the previous layer.
5. Circular rubber conveyor belt disk is used to keep the material level. It is placed on top of
the loose material and compaction takes place onto the disk. The sandy material tends to
climb up the side walls and the conveyor disk is used to keep the material more of less
level. The cover, being rubberized, tends to absorb of the compactive effort and would
result in a lower MDD. The MDD should increase if the disk was not used.
6. The hammer tends to drift more to the centre of the mould during compaction giving
more compaction to the centre than the outer sides. The material that climbs up the side
walls needs to be levelled after each layer to ensure a more even distribution of
compactive effort.
7. Compaction is undertaken by hand.
5.3 Atterberg
1. Plasticity Index (PI) undertaken using TMH1 methods
2. No 10-minute mixing period undertaken for the preparation of the sample for the LL
3. LS trough tapped when half filled. This is not necessary if material is non-plastic. It need
not be tapped but it would make more sense to do the taps at the end once all 3 layers
are filled in before striking off the excess material.
4. Striking off excess material should be a single action, not multiple times.
5. The material was non-plastic (NP) so LL was not undertaken and this activity could not be
evaluated.
6. Testing done from dry to wet as per TMH1
7. 10 mm block used to check for fall. It was not clear on the calibration of the block if it is
transferred verification from a caliper or if the block itself is calibrated.
5.4 General points
1. Calibration undertaken on major equipment by Protsurv and a Portuguese company.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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2. No control sheets used to verify measurements between calibrations. Balances are
checked monthly (as against daily checks).
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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6 SoilLab laboratory - Maputo
6.1 Overview
SoilLab makes use of rented property close to ANE offices in Maputo and is currently looking
to establish themselves in their own premises. They are affiliated to the South Africa SoilLab
group.
A good range of test methods is undertaken in the facility including concrete, geotechnical
investigations, aggregates and limited asphalt methods.
The following points where noted during the assessment of this facility on 22nd March
6.2 MDD/CBR
1. This laboratory also makes use of the rubber conveyor disk when compacting soils.
2. 5 samples made up for MDD & CBR demo.
3. Moisture sample taken at beginning of compaction.
4. Counts for the blows per layer varied from 65 – 55. Compaction was done by hand as there
was a power cut. The lab does have an automatic hammer, which is normally used given
that there is electricity.
5. Layer thinness is corrected by eye resulting in variable layer thicknesses. Correction is
mainly done on the final layer when it is easiest to see the height against the top of the
mould.
6. Water baths were not filled so no comment can be made on the depth of the water when
soaking CBR specimens.
6.3 Atterberg
1. The lab uses of a combination of TMH1 and AASHTO methods.
2. A 100g sample is used.
3. Mixing is done from wet to dry state
4. Grooving of LL sample is done to the back of the bowl. The groove should result in a clean
2 mm gap separating the material in the bowl into 2 more of less equal halves.
5. The LS trough is filled with 2 layers rather than 3 as per TMH1.
6. The LS trough is to be levelled with a single action and not multiple strokes.
7. The mixing was timed for 10 minutes.
6.4 General points
1. There were some possible table stability issues. Some tables were free standing and not
stable enough for balance readings.
2. Calibration of major equipment is undertaken by Geosol.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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7 JJR quarry
7.1 Overview
This is a very neat operation supplying crushed material to JJR contracts only. There are no
laboratory facilities on quarry site for testing. All testing is conducted at the main JJR facility
in Maputo. It is proposed that some basic testing facility e.g. grading FI & ALD should be
established at the facility for production control purposes.
7.2 Use of JJS Material in the PTS
The following points where noted during the visit to the facility regarding the appropriateness
of the material for granular testing and aggregate testing samples for the Proficiency Testing
Scheme (PTS).
1. Crushed material is most likely to be non-plastic (NP). (A sample of a plastic material (only
-0.425 mm fraction) will be sourced in Inhambane to test the laboratories’ capabilities for
testing plastic materials).
2. Concrete stone can be used for grading, FI & 10% FACT samples. ALD samples are not
available at the quarry.
3. Good sand source that can be used for SE (Sand Equivalent) if required.
Figure 7.1: Granular material at JJR Facility
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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8 JJR laboratory
8.1 Overview
This is a very neat and clean facility in all departments including asphalt, emulsion and
bitumen division. The facility has an asphalt plant on site with a large variety of construction
plant for all asphalt and surface treatment applications.
The following points where noted during the assessment of this facility on 22nd March.
8.2 General
1. No demo sample was available so the processes where spoken through. This could differ
from what is done in practice.
2. There was a request for information on calibration facilities in South Africa that could
assist with major equipment calibrations for JJR’s facility. This should be coordinated with
other facilities in Mozambique requiring calibration to save on the travel costs from SA.
8.3 Riffling
1. Pans used for riffling samples are held either vertically or horizontally into the riffles.
One of the methods needs to be adopted to reduce variability. Vertical methods are
used in SANS 3001 series.
2. Various riffler opening sizes are available.
8.4 MDD/CBR
3. TMH1 methods are used in the laboratory besides bitumen, which is ASTM based.
4. The base plate for the MDD & CBR compaction needs to be fixed to a concrete base.
Currently it is a loose plate which tends to move around under the hand compaction
movements. The same base is used for the asphalt briquette manufacturing.
5. Both manual and automatic hammers are available for soils. Manual hammers also
include the Proctor hammer.
6. Soaking is done in the same bath as for concrete curing which raises similar issues as seen
in the other laboratories around the water level for the CBR soaking.
7. No control sheets are used to record verifications of the measuring devices used.
8. Rubber conveyor disk are used for compaction with similar commentary relating to the
possible loss of compaction. They are only used for sandy type materials and not crushed
layer works materials.
8.5 Atterberg
1. All equipment looks acceptable although no control sheets were available to check on
the critical dimensions.
2. No material was available for demonstration proposes.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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8.6 Aggregates
1. Flakiness Gauges are available for both BS & TMH1 methods. Care is required to ensure
the correct gauge is used based in the sieve opening used for the material.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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9 Inhambane - ANE
The following points where noted during the assessment of this facility on 22nd March
9.1 General
1. ACV/10 % FACT device is not working at present.
9.2 Riffling
1. A good variety of rifflers is available – 6.7 mm, 20 mm & 25 mm. These are acceptable
for sand and other fine material but would need a larger opening size if crushed material
was used.
9.3 MDD/CBR
1. CBR bath water too high.
2. Mass of material per layer not weighed off & corrected where necessary.
3. No 30-minute soaking period.
4. No gauze below the soaking plate.
5. Soaking plate drainage holes not clean.
6. Soaking plate placed flat on floor of soaking bath therefore no place for water to drain
up into the specimen. Soaking bath is also used for concrete curing. Two baths are
available so one could be used for concrete and the other for CBR so the depth of water
can be correct for both applications.
7. Samples are covered with plastic to prevent moisture loss.
8. Hand compaction is used.
9. The baseplate is not fixed to floor. The lab is looking at casting a foundation and securing
bolts to do the compaction outside the main building.
10. Oil is used to lubricate the moulds.
11. No rubber conveyor disk used to assist with keeping the material level in the mould.
12. Hammer mass is only 4,300 g.
13. The lab use only 100 g for moisture determination – too small a sample to be
representative. Samples are taken for A, B & C moulds.
14. LEM calibration stickers were seen on major apparatus.
9.4 Atterberg
1. Oven thermometer only able to read up to 50 oC. Therefore, the lab is unable to confirm
drying temperatures of 105 – 110 oC.
2. Very large spatulas used for mixing.
3. 100 g mixed on glass plate.
4. No timing done on mixing process.
5. A wet to dry mixing process is used although TMH1 is the method being used.
6. Balance beam scales are used for measurements, not electronic balances.
7. Taps are applied quicker than 2 per second although they are constantly applied.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page 14
8. A large amount of the material was used for the moisture content determination – 40 g.
9. The LS trough was filled well although 2 strokes were used to level the top.
10. The groove was formed by a forward stroke, with material flowing together at 24 taps.
11. The grooving tool is a bit rusted at the tip.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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10 Chimoio - ANE
The following points where noted during the assessment of this facility on 22nd March
10.1 General
1. No thermometer, stop watch or weights < 500 g are used regularly to assist with
verification of the apparatus.
2. The rod for ACV/10% FACT and concrete slump is a Y16 rebar. Ends are not rounded.
3. No traceable calibration on the major equipment.
4. Bitumen testing apparatus is available for bitumen penetration and softening point,
5. Concrete cube crushing and a vibrating table for cube manufacture are available.
6. Sieve shakers are available.
10.2 MDD/CBR
1. Standard errors were observed as at other facilities, e.g.
a. Layers not measured and material per layer weighted off,
b. Soaking plate holes blocked,
c. Mould base not fixed to the floor,
d. 30-minute soak period not observed once water mixed in.
10.3 Atterberg
1. TMH1 & AASHTO methods combined into one.
2. LS trough is filled in a single lift.
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11 Nampula - ANE
The following points were noted during the assessment of this facility on 22nd March:
11.1 General
1. There are no timing devices in the facility.
2. A Teltru thermometer is used to check oven temperature but the probe point is bent.
3. Good selection of weights is available
4. All sieves conform to TMH1 sizes.
5. Flakiness gauge and ALD device are available and in good working order.
11.2 MDD/CBR
1. Hammer mass 4,457 g.
2. Mould base to be fixed to the floor
3. Sample not covered once mixed with water resulting in moisture loss during compaction
of the 5 layers.
4. Thin plastic canvas disk used as against filter paper.
5. Layers not checked, measured and mass per layer revised to get the correct heights. This
resulted in a large portion of the final layer being removed in preparing the surface after
compaction was completed.
6. Blows per layer varied from 65 – 44 per layer with hand compaction.
7. The moisture containers are possibly too small for representative samples of coarser
material. Tin capacity maximum of 500 g.
8. No 30-minute soak time after mixing in water.
9. Swell gauge set up well on marked mould rim.
10. Water level for CBR soak too high.
11. The lab requires 7 kg samples for coarser material although most facilities use 6 kg when
testing sandy material
11.3 Atterberg
1. Grooving tool looked fairly worn.
2. TMH1 method is used although the material is processed from wet to dry.
3. The material is mixed on a glass plate from wet to dry state.
4. A very large spatula used, which makes it difficult to manipulate the sample in the bowl.
5. The bowl is possibly over-filled and sample not placed parallel to the base plate. The
material was bowed to the back of the bowl in a semi-arch.
6. The 2nd point was done on an air-dried sample on the glass plate.
7. The trough was not filled in 3 portions and wet material was tapped into place and able
to flow quite easily.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
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11.4 Second laboratory facility (approx. 20 km outside of Nampula)
This is very well stocked with brand new equipment which mostly hasn’t been used. Most of
the equipment is in the original packaging. The equipment includes pans, hammers, DCP’s,
shovels, sample bags, sieve sets, presses, ignition oven, centrifuges (2 types), balances,
pipettes, Marshall press, automatic MDD hammer, concrete cubes, etc.
Protocols for Improving the Proficiency of Material Testing Laboratories in Mozambique
Page 18
12 Summary of main points observed
12.1 Mixing of methods between TMH1 and AASHTO
1. The MDD/CBR mould dimensions differ.
2. The mixing of material for the Atterberg LL is done wet to dry as against dry to wet.
3. Levelling of LL material in the bowl is not done well.
4. There are differing LS trough sizes.
12.2 Methods not being followed correctly
1. No timing for conditioning is undertaken in various methods
a. 10-minute mixing of PI samples,
b. 30-minute soaking of MDD & CBR samples.
2. Layers for MDD & CBR are not measured and mass per layer adjusted where necessary.
3. Base plate for compaction is not fixed to a concrete block on the floor.
4. Overfilling of water bath level for CBR soaking.
5. 6 kg samples used as against 7 kg per mould.
12.3 Additional steps or apparatus added to methods
1. Conveyor belting used to retain sandy type materials for MDD & CBR compaction.
2. Adding of dry material to wet LL material to dry. A similar process is used to dry PL
material but it is only rolled onto the outside.
12.4 Equipment calibration and verification
1. Very few facilities have calibration certificates that are traceable to international or
international standards.
2. Very little verification is undertaken to some fixed period of time (e.g. daily, weekly,
monthly, 6 monthly, annually) with records kept on the status of apparatus related to
the tolerances given in the methods. This refers to balances, ovens, hammer mass,
hammer fall and head dimensions, LL fall, etc.
3. Very few facilities have a master set of sieves to verify working sieves.
4. Thermometers, timers, mass pieces and calipers are not available in most facilities.
5. Most MDD/CBR hammers are too light in relation to the apparatus tolerances. In some
cases, the hammer was up to 100 g lighter (a difference of > 2 % specified).
12.5 Staff competency
1. No continued competency records of staff were observed.
2. Staff in all facilities were very responsive to comments made and extremely keen to
learn and develop their knowledge of the methods. This is very encouraging.
3. Most facilities have a small staff complement (less than 5 members), with qualifications
ranging from degrees and diplomas to in-house trained staff.
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4. The interaction with the CDS consultants was very open with questions being asked by
the staff members at all the facilities on the test methods being observed as well as
some enquiring about additional methods.
12.6 Test Methods
AASHTO methods have been proposed as standard for Mozambique, although the actual
methods used by the laboratories include TMH1, British Standards and various aspects from
AASHTO. The reasoning for proposing the AASHTO methods is due to the similarity of the
methods to TMH1. This however is problematic as the TMH1 methods have now been
replaced with the SANS 3001 series which differs in various aspects from TMH1. As TMH1 will
be discontinued in South Africa from the end of 2017 it is felt that the AASHTO method should
be replaced in Mozambique over time with the SANS 3001 series for consistency in the SADC
region.
This decision needs to be very carefully considered to ensure that the methods proposed are
followed in the laboratories and are not a combination of various methods used in the past.
Test methods are being mixed with regards to the preparation of samples, apparatus
dimensions, and method followed.
It could be difficult to force the laboratories to test by a method they are unfamiliar with. It
may be better to analyse the results by method as well as by a combination of methods to
assess the variability in the individual methods as well as when combined.
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13 The way forward
13.1 PTS Protocols
The following is a summary of the protocol to be used for the first round of the PTS.
1. No test methods will be specified in the pilot round e.g. TMH1 or AASHTO. Each
facility will undertake the test (MDD/CBR, etc.) in the manner they are used to. No
sieve sizes will be specified due to the different methods that may be utilized.
2. Sand from ANE borrow pit will be tested for:
1. Grading
2. PI
3. MDD/CBR
3. Crushed material from the JJR quarry will be tested for:
1. Grading
2. PI
3. MDD/CBR
4. Plastic material obtained by ANE from Inhambane will be tested for:
1. PI only on -0.425 mm fraction
5. Single sized aggregate material from the JJR quarry will be tested for:
1. Grading
2. FI
3. ALD (As the material is a concrete stone, the ALD may not show a reliable result.
However, the process may point to basic testing errors which would assist in
identifying issues that need to be addressed).
4. ACV
5. 10% FACT
The full Draft Protocol is included in Annex A.
13.2 Follow-up PTS rounds
The provisional timing for the PTS rounds is as follows:
a. Round 1 – May/June analysed by B Pearce
b. Round 2 – August – analysed by LEM/ANE and reviewed by B Pearce
c. Round 3 – October - analysed by LEM/ANE and reviewed by B Pearce
13.3 Participating Laboratories
Samples will be sent to all eight laboratories that participated in the initial visit. However,
training and support will only be provided to the government laboratories in Maputo and the
provinces. Samples will also be sent to two SANAS accredited laboratories in South Africa.
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Page A1
Annex A: Draft Protocol for First Round of PTS
See separate Word file